1. Field of the Invention
The present invention relates to a soft-magnetic thin film and a magnetic head using this soft-magnetic thin film.
2. Description of the Prior Art
Recently, in the field of magnetic recording, with increase of the signal recording density and the recording/reproduction frequency, it has become extremely important to obtain a high coercive force of a magnetic recording medium which in turn requires a high saturation magnetic flux density of a magnetic head.
To cope with this, as a magnetic head capable of high density recording on a magnetic recording medium having a high coercive force and enabling to obtain a high electromagnetic conversion efficiency, there has been implemented into practice a layered type magnetic head having a magnetic path which is entirely constituted by a magnetic film having a saturation magnetic flux density and a high magnetic permeability. Such a magnetic head requires a soft-magnetic thin film having a magnetic isotropy having a high magnetic permeability in any directions because a loop-shaped magnetic path is formed during recording and reproduction.
As has been described above, the soft-magnetic thin film used in a magnetic head should have a high magnetic permeability and a magnetic isotropy.
By the way, in order to obtain the magnetic isotropy of a soft-magnetic thin film used in the layered type magnetic head, for example, during or after formation of a soft magnetic thin film, a rotational magnetic field is applied to the soft magnetic thin film for inducing a magnetic isotropy.
However, this method for producing a magnetic head having a soft magnetic thin film through the aforementioned application of a rotational magnetic field has a problem that a complicated film formation is required and a number of production processes is increased, which increase production costs.
Moreover, in a mass production of a magnetic head, film formation is carried out by mounting a plurality of non-magnetic substrates in a film forming apparatus for magnetic film formation. Consequently, the non-magnetic substrates are covered with soft magnetic films having different incident angles of film formation. The soft magnetic thin film having different angles of film formation have different magnetic isotropy and different magnetic permeability values, causing a magnetic anisotropy.